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Who will have the last word?

Gordon Brown will make the most important speech of his career tomorrow, when he stands before the Labour conference as the heir apparent. But frontrunners have fallen at the last hurdle before. The top job is Brown's to lose. Then just over 24 hours later Tony Blair takes centre stage ...

Tony Blair is an early bird these days. He has taken to rising at 6am, for an uninterrupted two-and-a-half hours' writing before the world wakes up: he scrawls longhand, in his study overlooking the rose garden at Chequers, avoiding the computer he was never terribly good at using.

Once, his press secretary, Alastair Campbell, would hone his phrases to tabloid-pleasing perfection for the annual conference speech, the biggest oratorical occasion of the Prime Minister's year. Teams of up to nine people would also have a hand in crafting it. For his valedictory address to party conference as Labour leader - the last emotional farewell to his party, delivered the day after Gordon Brown's critical eve-of-leadership speech, and what one former staffer describes as 'one of the key moments in British politics in the past 10 years' - one might expect a cast of dozens.

But that's not how it is. This time, says a Downing Street source, the speech is '100 per cent him', although he has bounced ideas off a few intimates - Campbell included: he delivered a draft almost five days ago. Which means Blair is determined on his theme: the party must face the public rather than navel-gaze about its leadership.

'In 2001, immediately after 9/11, Tony just knew exactly what he was going to say: he produced a polished draft well before conference,' explains one former aide. 'But in 2003 when we were trying to make the arguments about renewing Labour, it was much more difficult. We commissioned intellectuals and experts and politicians to come up with ideas: it was a more deliberative process.'

Blair has a difficult tone to strike - sufficiently emotional to mark the end of an era, without wallowing in the past; and sketching out the future without appearing to bind his successors. Meanwhile, every syllable will be scrutinised for clues about the succession.

But in an odd way, the pressure is off. In 12 years of leadership speeches, the Prime Minister has coped with being drowned out by a protester's rape alarm, pressured to apologise for Iraq, besieged by pro-hunting protesters and berated over Clause Four. At least this time, he has already confronted the trickiest issue - confirming his departure - before he opens his mouth.

For the Chancellor, the challenge is: to achieve grandeur, yet without seeming to give the impression that he thinks the leadership is in the bag; graciously to acknowledge colleagues, preferably not through gritted teeth; and to inspire Labour members to back him, but engage with the nation beyond. After David Davis made a hash of his leadership bid at last year's Tory conference, Brown knows a frontrunner can lose it all with one substandard speech: and worst of all, he will go first: Blair will not only be able to knock him swiftly off the front pages, but also to alter his own text on Tuesday in response to Brown's 27 hours earlier.

For the first time in years, the two men have discussed the themes of their speeches, although neither lets the other see the complete text. But the trickiest parts will still be those sections relating to one another.

Brown has certainly penned some generous tributes to the Prime Minister, say his aides, while, for Blair, warmth about the Chancellor is often surprisingly easy. 'Their relationship is much more complex than people think,' says one friend. 'Despite everything, somewhere at the back of his mind Tony still saw Gordon as his older brother who had the real experience, who really strategically knew where to go.'

But that does not mean Blair will provide what the Chancellor's friends seek: a declaration that he wants Brown to succeed him. Already rumours are flying of two draft speeches being drawn up: one conciliatory if the Prime Minister warmly endorses Brown in a pre-conference TV interview this morning, an aggressive one if not.

When Brown grips the lectern tomorrow morning, it will be the culmination of almost a year's preparation. The two days he spent in New York last week, hobnobbing with Bill Clinton and visiting Ground Zero, were only the latest steps in a meticulous campaign grooming him for Number 10.

Just as Margaret Thatcher softened her image with frilly blouses and elocution lessons, the Iron Chancellor has been cloaking his armour. Some of the makeover has been plausible, revealing the genuine warmth that comes out in Brown around his children: at a party for journalists at Number 11 a couple of weeks ago, his toddler son John played under guests' feet.

Others have been toe-curlingly improbable, such as this summer's revelations that he bought his pants from M&S, and thought the Arctic Monkeys 'really wake you up in the morning'.

But the most authentic step is probably this week's launch of a book of his collected speeches, edited by Wilf Stevenson, director of the Brownite Smith Institute. Each is prefaced with glowing essays from the great and the good, from JK Rowling explaining how his measures for children 'would have made a real difference to my family's life' when she was poor to Al Gore claiming to be an 'unabashed and enthusiastic admirer of Gordon'.

This is how Brown himself wants to be seen: an intellectual colossus who earns the respect of everyone from Kofi Annan to Nelson Mandela. Mandela, however, does not have a vote at the next election. And among those who do, last week's Guardian ICM poll made unflattering reading.

The poll suggested that Brown is considered more likely than David Cameron to stab people in the back, to have a less likeable personality and to be less honest. Hence the pressure for Brown to show that he knows how to turn those gloomy figures around. 'The test,' says a senior Blairite, 'is electability.'

The Chancellor started mapping out his thinking in August, traditionally the month when he retreats to his Queensferry home. He writes out his own first draft: a handful of respected intimates are shown it for comment, but the drafts rarely undergo much alteration before being delivered with the thundering passion of a preacher.

This time, however, he is under pressure to change the record. 'Everybody's got used to the steamroller Brown,' says a Cabinet aide. 'He needs to be more conversational'. He may also need to be less honest: Blairites have not forgotten the year he warmly namechecked most of the Cabinet, trying to show his collegiate side, but deliberately omitted his great enemy Alan Milburn.

His friends however argue that he can't win: if he sticks to fiery oratory he will be accused of trying to outdo Blair; if he tries something new, it will be dismissed as fake.

When the American pollster Frank Luntz showed footage of the Tory leadership challengers to floating voters almost a year ago, in a film for BBC2's Newsnight, it turned the contest upside down: Cameron emerged unexpectedly as a runaway winner. Luntz has spent the past few days repeating the exercise - only this time with Brown versus potential rivals Alan Johnson, John Reid, Alan Milburn, David Miliband and the backbencher John McDonnell. The results are due on Monday night. If Brown were outstripped by one or more of them, what then?

One veteran ex-minister describes the mood in the party as 'one of fear', not least of another eruption at conference that would send the polls into freefall: 'Right now, people just want it all to go away. It's not going to, but that's what they want.'

A telephone survey of constituency chairmen and women by Downing Street aides, done to gauge the party's mood, suggests some annoyance with the Brownite operation, but a continuing assumption that he will be leader.

The conference floor is being mollified, too. While there will be a showdown with the unions on NHS privatisation and pensions, grassroots motions on many contentious issues - Iraq or Trident - were ruled out of order at last week's meeting of National Executive Committee.

And while the fringe will resound to the battle cries of rival deputy candidates, that fight has yet to capture the imagination. Reluctant to make spending commitments, or say anything that will upset Brown, or break Cabinet ranks, the would-be deputies are struggling so far to interest their colleagues, let alone the wider public. Which leaves, once again, the party looking to Blair - and now also to Brown - for inspiration. 'The purpose of the conference, let alone the speech, is to show that Labour never loses sight of the public,' says Campbell, who argues his former boss has not stopped believing the next election can be won.

For Blair, time has almost run out. But the argument he wants to make this week is that the best of Blairism survives him; that the Tories are making mistakes that can be exploited, so long as Labour stops the infighting. The choice of Manchester, symbol of urban renaissance and optimism when it was rebuilt after the IRA bomb in 1996, as this week's conference venue is no accident. Twenty-seven hours divide the two men's speeches this week; just over a day in which so much can go very wrong. If they do, Labour - and the Government - may never recover.

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